As a marketer, you have a bucket list of tactics to try — things that you\u2019ll get to one day. The challenge is which tactics will be the most effective, with the least effort. The proverbial \u201clow-hanging fruit.\u201dYou know that in order for a business to thrive, it needs to sell more than one thing to each customer\u2026 maybe you\u2019ve even tried to do just that. Or maybe you haven\u2019t even thought about it before.In either case, there\u2019s a good chance you\u2019re leaving money on the table.That\u2019s because the truth is acquiring a new customer is hard (and expensive). So wouldn\u2019t it be nice if it was possible to sell them more than one thing at a time, without chasing customers away?Fortunately, it is \u2014 in fact, that\u2019s what upsell funnels are all about.What is an Upsell Funnel?When most people hear the word \u201cupsell\u201d they probably think of a McDonald\u2019s drive-thru cashier saying, \u201cDo you want fries with that?\u201dThat line has undoubtedly made McDonald\u2019s billions of dollars, but that\u2019s what we\u2019d call a pre-purchase upsell. For course authors, product creators, and self-funded businesses, trying to sneak in an extra product before you\u2019ve closed the deal may lead a prospect to hold off on clicking \u201cbuy.\u201dSo, for these kinds of businesses, what I recommend instead is a post-purchase upsell.A post-purchase upsell funnel happens after the prospect has already completed their transaction\u2026 after they have already paid. This allows you to avoid discouraging them from purchasing that first product, while still creating an opportunity to increase the value of the sale.Let\u2019s look at an example.John has been scoping out an online course about learning to launch a podcast. He\u2019s decided to take the plunge, and purchase a course from PodcastingBeginner.com (a fictional site, made up entirely for the purpose of this example).He adds the course to his cart and goes through the process of checking out. After entering his credit card information and clicking buy, he\u2019s greeted with a thank you page \u2014 and beneath a message that says \u201cThank you for purchasing Launch a Podcast in 30 days\u201d is a note asking him if he\u2019d like to add on a package of 6 interviews with professional podcasters, each making $5,000 or more from podcasting each month \u2014 a series full of tips and best practices to help new podcasts do the same, which usually sells for $250 or more \u2014 for an additional $100.That is a post purchase upsell funnel. And when done correctly, it\u2019s a bit like printing free money. In fact, on average, they generally increase revenue by around 30%.So let\u2019s take a look at why they work.Using Psychology to Make a Second SaleI\u2019m fond of saying that Marketing is just applied Psychology. So let\u2019s look at the psychology of WHY post-purchase upsells work so well.Imagine for a minute that someone knocked on your door and asked you to place a large, gaudy sign reading \u201cDrive Carefully\u201d in your front yard, practically blocking your house. You\u2019d probably laugh in their face \u2014 you might even slam the door.Yet in the mid-1960s, psychologists Jonathan Freedman and Scott Fraser did an experiment that led 76% of homeowners included in the study to agree to exactly that. The experiment was designed to look at what most salespeople consider \u201cgetting a foot in the door\u201d and what is more properly known as the consistency principle.The concept is simple enough: people want to make decisions that are consistent with the decisions they\u2019ve made in the past.Robert Cialdini talks about the concept in some length in his book, Influence: The Psychology of Persuasion. We try to be consistent because doing so is a survival skill \u2014\u00a0it gives us a helpful shortcut. We think about something once, and then never have to think about it again.Which means that when the consistency principle is triggered, decisions are made almost automatically.So, how did Freedman and Fraser get 76% of homeowners in their experiment to agree to have a large sign placed in their yard?They had a volunteer stop by a few weeks before making the request and asked those same homeowners to display a smaller, three-inch sign that read \u201cBe a Safe Driver.\u201dAnd, in case you\u2019re thinking people back then were just more willing to do things for the greater good than folks are today, there\u2019s one more fact that I\u2019ve left out.Like any good experiment, Freedman and Fraser also had a control group. For this second group of homeowners, they only made the second request \u2014\u00a0going straight for the larger ask of the billboard in their front lawn. Their success rate? A much smaller 17%.I think you\u2019ll agree that that\u2019s a pretty dramatic difference\u2026 and that the consistency principle is a pretty powerful tool.Getting to Yes: Using Consistency In Your Upsell Funnel to Get More SalesOf course, putting the consistency principle to work for you, and creating a successful upsell funnel isn\u2019t quite as simple as just slapping up another product and calling it done.As with all things in life, there are some things that are more effective than others. In my experience, there are three post funnel upsell concepts that work best.Upgrade at a DiscountLike in our example above about the podcasting course, this type of post-purchase upsell offers another package or product that provides additional value at a discounted rate.That discount is directly tied to the customer having just made a previous purchase \u2014 so you might use language like, \u201cAs our thank you to you, we\u2019d like to offer you a discount on\u2026\u201d and then name the item you\u2019re offering as an upsell.This is the same strategy as the \u201cSuper-Size\u201d strategy used at McDonalds in the 90s. For a LOW, LOW price, you can get even more!Upsell a SubscriptionIn this type of upsell funnel, the customer purchases a product (or maybe a few products), and you offer them a recurring supply of goods or services for a monthly fee.Think buying a printer, and having the manufacturer offer to send you ink anytime you run out, if you pay them a few dollars a month for a subscription service. This is also common with products like dog food\u2026 but it\u2019s not limited to physical goods.For those with online courses, this may be access to a forum, a mastermind, or weekly \u201coffice hours\u201d where they can ask you questions live.Selling a Secondary (Related) ProductsFinally, the third option for a post-purchase upsell funnel is to offer a related product at its usual price\u2026 and that price does not necessarily have to be lower than the price of that first purchase.You might try to upsell them to a higher level of the course they just purchased, or even sell them on a whole new course that serves a related need. The important thing here is to test your funnels, and use dollars as the key performance indicator (KPI).One of the most surprising things is that the upsell product doesn\u2019t necessarily need to be cheaper than the original product. In fact, we\u2019ve seen that offering a $1,000 product as an upsell on a $300 purchase can actually bring in MORE revenue than going with a cheaper product.After all, if you use a $1,000 product as your upsell item, and sell 4 of them in a month that\u2019s more profitable than if you use a $50 product as your upsell item and sell 15.Getting to Yes \u2014 Again and Again.Finally, I want to leave you with the idea that a post-purchase upsell funnel isn\u2019t limited to 2 steps. If a shopper says yes, and then says yes again, why not ask a third time?That said, if they say no twice in a row, I usually recommend sending them to a final thank you page without another product. More than that and they\u2019re likely to leave the site\u2026 and we\u2019d much rather they stick around and leave the door open for more sales later on.What are some great Upsell Strategies that you\u2019ve seen, or implemented, in the past? I\u2019d love to hear about them! Let me know in the comments below.